Demountable chassis



March 23, 1954 Filed Dec. 2, 1949 J. C. SIMS, JR., EI'AL DEMOUNTABLECHASSIS 3 Sheets-Sheet l IN V EN TORS.

March 23, 1954 J, c, suvls, JR,, ETAL 2,673,342

DEMOUNTABLE CHASSIS Filed Dec. 2, 1949 3 Sheets-Sheet 2 23, 1954 Q s sJR" ETAL Filed Dec. 2, 1949 DEMOUNTABLE CHASSIS 3 Sheets-Sheet 3Patented Mar. 23, 1954 v DEMOUNTABLE CHASSIS John 0. Sims, Jr.,Springhouse, and John Presper Eckert, Jr., Philadelphia, Pa., assignorsto Eckert-Mauchly Computer Corporation, Philadelphia, Pa., a corporationof Pennsylvania I Application December 2, 1949, Serial No. 130,842 9Claims. (01. 340367) This invention relates generally to an electrontube chassis and more particularly to a demountable chassis adapted-foruse in a system for the electrical storage of intelligence.-

Although the conventional cathode ray tube has been adapted to manydiverse uses, it has not prior to this time been utilized as'a memorystorage unit for digital computers. Reference is had to U. S.application Serial Number 98,178 of John Presper Eckert, J1'., andHerman Lukoif, filed June 10, 1949, entitled Information Storage System,for a detailed description of the system to which the invention relatesas a partial embodiment thereof.

The aforesaid information storage system re-' quires a structure adaptedto support and electrically shield-a large electron discharge tube andcertain new elements-used in combination therewith, while stillallowinga view of the face of said electron tube. Also required isafunctionally new element which picks up intelligence from the face of anelectron tube. The present invention described in detail below isa newand improved chassis providing all the aforesaid re quirements.

Accordingly, it is a primary object of the present invention to providea new and improved chassis for the mounting of electricdischarge tubes.

Another object of the invention is to provide a new and improved chassiswhich is demountable' and houses a cathode ray tube and the electricalcomponents associated therewith.

Yet another object of the invention is to provide a new and improveddemountable chassis for use in an information storage system whichhouses a cathode ray tube and circuits associated therewith and allowsdirect control of said circuits from the front panel of said chassis.

Still another object of this invention is to provide a chassis which hasits electrical components disposed to give substantially improvedoperating performance.

A further object is to provide a new and improved chassis adapted to.electrostatically pick up signals on the face of a conventional cathoderay tube or an electron tube similar thereto.

Yet another object of the invention is to provide a new and improvedchassis which furnishes a substantially improved signal from the face ofa conventional cathode ray tube.

Still another object of this invention is to provide a new and improvedchassis which materially improves the signal to noise ratio in thesignal output of electrical circuits contained therein.

Another object of this invention is to provide a new and improvedchassis which furnishes sub-- stantial magnetic and electric shieldingfor the face as well as the walls of a cathode ray tube.

A further object of the invention is to provide a new and improvedchassis for use in an information storage system which is quicklyandeasily mounted and demounted with a minimumvide a demountable chassisfor large electric dis-- charge tubes having simplified mechanicalconstruction.

Other objects and advantages of the inventionwill in part be obvious andin part be described when the following description is read inconjunction with the drawings, in which:

Figure l is a front view of a demountable chassis containing an electrontube,

Figure 2 is a side view of Figure 1 partially cu away,

Figure 3 is an end view of Figure 2, Figure 4 is a sectional view of thesupporting panel ll shown along the.v line 4, 4 in Figure 2, Figure 5 isan exploded View of the removable electron tube shield screen and shieldring, and a portion of the cylindricalshielding body howni inFigure 2,and,

Figure 6 is a view of thesignal pickup screenv and its supportingframe.Like reference numerals designate like parts throughout the severalviews.-

Referring now to the drawings, the numeral ll] designates thechassisfront panel which has. a rectangular outer configuration. and'ismade of electrically conductivematerial. Likewise and i2 designate anintermediate panel and an end panel, respectively which,.however, aremade of an electrically non-conductive material. v The front panel Iandintermediate panel I'I have their respective corners connectedby a,set of four risers i 3. Each -riser I3 has one end tapped for attachmentto the front panel 10 by machine screw M which passes throughacorresponding aperture in the front panel In. The

other extremity of each of said risers I3 hasa threaded portion. on areduced diameter which passes through an aperture in a corner of saidintermediate panel I I. vThe said riser ends l3 are.

secured to the said intermediate panel II by another set of fourinsulating risers I5 which are adapted to threadedly engage to theprotruding studs of said risers l3. The remaining ends of said fourrisers I5 are secured to said end panel I2 in the same manner in whichsaid front panel I is attached to said risers I3 as shown in Figure 2.The panels I0, II and I2 are rigidly positioned by risers I3 and I5 sothat they respectively lie behind each other in essentially parallelplanes.

A conductive magnetic shielding body It is formed by welding acylindrical section to a conical section along two of their edges ofequal configuration. The said body I6, being formed from sheet metal, isa hollow and shell like structure, which is positioned by two apertureswhich are found, respectively, in panels I0 and H. The body I6 isattached by means of brackets I1 and I8, respectively, to panels I0 andII. A clamp 48 is supported by panel II in alignment with the aperturein said panel II. By this means the neck of an electron tube 24, whichrests within the body I6, is clamped in a fixed position as it passesthrough said aperture in panel I I.

Insulating panel II as well as insulating panel I 2, supports a numberof potentiometers i9 either by their shanks or by means of stand-offs20. The said potentiometers I9 are controlled from the front panel bymeans of shaft extensions 2I which are connected to the potentiometershafts 22 by flexible insulating couplings 23. Said shaft extensions arerotatably mounted in the front panel In by means of fittings 25 whichallow said extension shaft ends 28 to project through said panel iii.The said projecting extension shaft ends 25 are slotted to provide forrotation of said shaft 2I by means of a screw driver.

Referring to Figure 3, end panel I2 supports two sockets A? forreceiving a pair of electron tubes used in the blanking and deflectioncircuits for electron tube 24, trimmers 21' and a plurality of malecontact points 53 which respectively contact their female counterpartwhen the above described mechanical structure or chassis is mounted in aframe adapted therefor (not shown) The said male and female contacts aremore particularly described in pending U. S. application of John PresperEckert, Jr., John C. Sims, Jr., and Isaac L. Auerbach, entitledStructure for Electrical Apparatus, Serial Number 77,132, filed February18, 1949, now Patent No. 2,579,141.

Referring to Figure 2, it can be seen that the base of electron tube 24,the terminals of potentiometers I9, the lugs of electron tube sockets41, terminals of trimmers 2?, and male contact point connections are alllocalized in the region between panels II and I2. This localizationwhich is advantageous from both mechanical and electricalconsiderations, yet allows front panel control of potentiometers I9through the utilization of said extension shafts 2|.

Referring to Figures 1 and 2, the above said body I6 is designed so thata portion of its cylindrical section extends beyond the surface of panelI0 and the face of electron tube 24 so that a shield ring and screenring assembly, 28 and 34 respectively, can be contained therein.

Figure 5 shows in greater detail shield ring 28 and metallic shieldscreen 29 which is soldered to said ring 28. The shield ring 28 hasthree tapped holes 30 spaced 120 degrees apart, each receiving a thumbscrew 3 I. The said shield ring 28, which has an outside diameter equalto the inside diameter of said extended cylindrical por- 4 tion of bodyI6 is supported within said cylindrical portion, enclosing end of saidbody I6.

Three L-brackets 32 are spot welded at points evenly spaced around theperiphery and along the outer edge of the extended portion of said bodyIS. The shield ring 28 is held above said position by clamping thL-brackets 32 between the shield ring 28 and thumb screws 3| by means oftightening thumb screws 3|. The shield ring has three cut-out portions33 around its circumference to allow for the clearance of said brackets32 when the shield ring 28 is replaced or removed. Substantiallycomplete shielding of electron tube 24 against interference fromexternal electrostatic 'magnetic fields is provided when said electrontube 24 is contained within body I6, and shield ring 28 containing ashielding electrode or shield screen 29 is in place.

Referring to Figures 2 and 6, the inner screen ring 34 is made of aninsulating material and proportioned to fit into shield-body I6. Threebrackets 35 are attached to said inner ring 34 being evenly spacedapart) along its outer circumference. The ends of said three brackets35, pass through three holes 36 in shield ring 28 and have a nut andlock nut 31 securely fixed upon the threaded end portion of the saidbrackets 35. (Figure 2.) The springs 38 which coil about the cylindricalportion of brackets 35 exert a force tending to keep the nuts 31 againstthe face of said shield ring 28.

Referring to Figure 6 for greater detail, a

signal pickup electrode which may be a fine meshed metallic screen 39which is stretched over the inner ring 34 and held in position by beingwedged between the outer circumference of inner screen ring 34 and theinner circumference of an outer screen ring 43. screen ring is made ofan insulating material and has three guide pins 4| around its peripherywhich help to center said outer screen ring 40 inside the shielding bodyI6.

The position of the nuts 31 on the bracket 35 can be adjusted so thatsaid meshed screen 39 will be'forced under the tension of springs 38 tocontact with the glass face of the electron tube 24.

A small hole 42 is drilled in the upper portion of the shielding body I6nearest the meshed screen 39 to allow an electrical connection betweensai meshed screen 39 and a preamplifier 43 (shielded by cover 49)mounted on the front panel I0 directly above the shielding body IS.

A male contact 44, similar to said contacts so,

is located on panel I0 behind said preamplifier 43. meshed screen 39 isshielded first within body I6, passes almost directly into the shieldedpreamplifier 43, and then through the contact point 44 when the chassisis mounted, into a shielded transmission line (not shown) thusminimizing signal distortion due to interference from external magneticelectrostatic fields.

Considering the herein described demountable V handles 45 havingthreaded ends 46 which turninto the said receiving frame. This insuresthat a contact pressure will be maintained at said Said outer By thisarrangement a signal picked up on contacts 50 and ift, thus maintainggood ,electrir cal connections between the. electrical circuits of thechassis and those circuits external to said chassis. The two handles 45also serve to electrically connect the shielding body it to thereceiving frame through the electrically conductive panel I0, andbrackets ll.

The demountable chassis is a complete unit in itself, having containedwithin it all circuits associated with the operation and control of acathode ray tube. For instance, it contains electrical circuits whichamplify the signals received through contacts 50, sotheir intensity issuitable for the proper operation of the electron tube 24. Control ofthe electrical circuits is possible from the front panel it) while thechassis is mounted and in operation by shafts 2!, as describedpreviously, The chassisalso provides for. picking up a signal from theface of said electron. tube 24 and preamplifying it before it passesfrom said chassis to a transmission line.

Although magnetically and electrostatically shielded the face ofelectron tube 24 is, however, still visible from the front of thechassis through shield screen 29 and meshed screen 39, thereby allowingthe necessary adjustments to be made in the electrical control circuitsto insure proper operation of said electron tube 24.

All components mounted in the chassis are easily accessible for quickrepair or replacement. Electron tube 25 is removed from the chassis byfirst removing the shield ring 28 and screen ring 34 assemblies,loosening clamp 48 around the neck of electron tube 2 3, and the tubesocket (not shown) connected to the base of said electron tube 24. Nowthe said electron tube 24 can be moved forward out of the chassisthrough the front panel H]. The electron tube 24 can now be replaced insaid chassis and said other components made to reassume their formeroperative positions.

Any number of chassis can be placed in a receiving frame depending onthe needs of the electrical system in which they may be utilized. Eachchassis may be quickly and easily removed and replaced by a sparechassis for nearly uninterrupted operation of said system in the case ofthe malfunctioning of one of said chassis.

It will be obvious to those skilled in the art that many modificationsand variations of this invention are possible without essentiallydeparting from the spirit of the invention.

What is claimed is:

1. In apparatus adapted to utilize an electric discharge valve having anenvelope with an information receiving face, an electrically conductivebody adapted to magnetically shield said valve, a first electricallyconductive transparent electrode secured at one end of said magneticshield and in electrical engagement therewith, a second electricallyconductive transparent electrode insulatedly secured within the volumebounded by said magnetic shield and said first electrode, and adapted toexternally engage the face of said electron valve in a region in whichsaid second electrode is rendered electrically responsive to theinformation appearing at said face and is rendered non-responsive toambient electromagnetic disturbances, and a conductive connection tosaid second electrode leading outside said volume.

2. In apparatus adapted to utilize an electric discharge valve having anenvelope with an information receiving face, first and second relativelyspaced apertured members, an open ended electrically conductivemagnetic. shield for :said

valve disposed within saidapertures and. support-1 ed from said firstand secondmembersa first electrically conductive transparent electrodeoverlappingly secured at one end of said magnetic shield and inelectrical engagement therewith, a

second electrically conductive transparent elece.

ductive connection to said. second electrode. adapted, for cooperationwith apparatus .ex-

ternalto the shield assembly.

In apparatus adapted to utilize an electric discharge valve having anenvelope with anine. formation receiving face, a first apertured bodyadapted to electrically shield the walls of. said valve, a secondconductive electrostaticshielding body enclosing an aperture in saidfirst body, a signal pick up electrode shielded with respect to ambientelectromagnetic disturbances by said first and second bodies and adaptedto receive signals from said face, an electrical circuit operativelyconnected with said signal pick up electrode, and a common membersupporting said first and second bodies and said signal pick upelectrode.

4. In apparatus adapted to utilize an electric discharge valve having anenvelope with an information receiving face, a first apertured bodyadapted to magnetically and electrostatically shield the walls of saidvalve, a second conductive electrostatic shielding body enclosing anaperture in said first body, an electrically conductive mesh screenshielded with respect to ambient electromagnetic disturbances andsupported by said first and second bodies, a removable frame adapted forholding said meshed screen in physical contact with said face, ashielded preamplifier operatively connected with said meshed screen,means coupled to said first and second bodies and said shieldedpreamplifier to maintain said bodies and said preamplifier at a constantpotential, and a common member supporting said first and second bodiesand also supporting said preamplifier adjoining said signal pick upelectrode.

5. In apparatus adapted to utilize an electric discharge valve having anenvelope with an information receiving face, an apertured body adaptedto magnetically and electrostatically shield the walls of said valve, anelectrically conductive mesh screen, a removable frame supporting saidmeshed screen in the aperture of said body, a signal pick up electrodeshielded with respect to ambient electromagnetic disturbances andsupported by said body and adapted to engage said face, a shieldedpreamplifier operatively connected with said signal pick up electrode,means coupled to said body, said screen and said preamplifier tomaintain said body, said screen and said preamplifier at a constantpotential, and a common member supporting said apertured body and saidpreamplifier.

6. In combination, an electric discharge valve comprising an envelopedefining a working chamber and a source of mobile electric chargecarriers disposed within said chamber, said envelope including aninformation receiving face subject to charge carrier bombardment, asignal pick up electrode resiliently urged into mechanical engagementwith the side of said face lying withoutsaid chamber, a shieldingelectrode insulatedly supported in spaced shielding relationship with asurface of said signal pick up electrode remote from said face to shieldsaid signal pick up electrode from ambient electromagnetic disturbances,and a common structure supporting said valve and both electrodes.

7. The combination as set forth in claim 6 wherein both said signal pickup electrode and said shielding electrode are transparent.

8. In an electric valve housing structure combining shielding andsensing properties and adapted for cooperation with a valve having aninformation receiving face, an electrically conductive body surroundingand magnetically shielding said valve and provided with an apertureexposing said face, a first electrically conductive shielding electrodeurged into mechanical and electrical engagement with said body andmounted about said aperture to define a region which is bounded by saidfirst electrode and said face and which is free from ambientelectromagnetic disturbances, and a second electrically conductiveelectrode responsive to information appearing at said face disposed andinsulatedly secured within said region.

9. The electric valve housing structure as set forth in claim 8 whereinboth said first and second electrodes are transparent.

JOHN C. SIMS, JR.

JOHN PRESPER ECKERT, J 21,

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,181,132 Kallmeyer Nov. 28, 1939 2,292,919 Barco Aug. 11,1942 2,403,239 Rose July 2, 1946 2,404,764 Hayes July 23, 1946 2,440,260Gall Apr. 27, 1948 2,534,369 Ress Dec. 19, 1950

